Showing papers on "Sialic acid published in 1985"
TL;DR: Findings suggest that in rat hepatocytes sialylation of N-linked glycoproteins occurs in the complex formed by the trans-cisternae and theTrans-tubular network of Golgi apparatus.
433 citations
TL;DR: Results strongly suggest that the glycoprotein components of the lysosomal membrane are synthesized in the rough endoplasmic reticulum and terminally glycosylated in the Golgi before delivery to lysOSomes.
Abstract: Three glycoprotein antigens (120, 100, and 80 kD) were detected by mono- and/or polyclonal antibodies generated by immunization with highly purified rat liver lysosomal membranes. All of the antigens were judged to be integral membrane proteins based on the binding of Triton X-114. By immunofluorescence on normal rat kidney cells, a mouse monoclonal antibody to the 120-kD antigen co-stained with a polyclonal rabbit antibody that detected the 100- and 80-kD antigens as well as with antibodies to acid phosphatase, indicating that these antigens are preferentially localized in lysosomes. Few 120-kD-positive structures were found to be negative for acid phosphatase, suggesting that the antigen was not concentrated in organelles such as endosomes, which lack acid phosphatase. Immunoperoxidase cytochemistry also showed little reactivity in Golgi cisternae, coated vesicles, or on the plasma membrane. Digestion with endo-beta-N-acetylglucosaminidase H (Endo H) and endo-beta-N-acetylglucosaminidase F (Endo F) demonstrated that each of the antigens contained multiple N-linked oligosaccharide chains, most of which were of the complex (Endo H-resistant) type. The 120-kD protein was very heavily glycosylated, having at least 18 N-linked chains. It was also rich in sialic acid, since neuraminidase digestion increased the pI of the 120-kD protein from less than 4 to greater than 8. Taken together, these results strongly suggest that the glycoprotein components of the lysosomal membrane are synthesized in the rough endoplasmic reticulum and terminally glycosylated in the Golgi before delivery to lysosomes. We have provisionally designated these antigens lysosomal membrane glycoproteins lgp120, lgp100, lgp80.
297 citations
TL;DR: Results provide the first direct evidence that the polysialic acid on NCAM has a regulatory effect on adhesion between living cells, and that the amount of this carbohydrate is critical for the normal morphogenesis of nerve tissue.
Abstract: A phage endoneuraminidase that specifically cleaves alpha-2, 8-linked polysialic acid has been found to be a useful probe for examining the biological role of this sugar moiety on the neural cell adhesion molecule (NCAM). The enzyme caused a 3.3-fold increase in the rate of NCAM-dependent aggregation of membrane vesicles from chicken embryonic brain, without the nonspecific effects previously encountered with the use of exoneuraminidases. The enhancement of aggregation was closely correlated with removal of sialic acid as assessed by electrophoretic mobility. Extension of this analysis to cultures of spinal ganglia indicated that removal of sialic acid by the endoneuraminidase results in an increase in the thickness of neurite bundles. This enhancement of fasciculation was reversed by addition of anti-NCAM Fab, suggesting that the enzyme treatment was not toxic and did not produce nonspecific effects on adhesion. Injection of the enzyme into the eyes of 3.5-d chicken embryos consistently produced a striking array of abnormalities in those parts of the neural retina that contained the highest concentrations of NCAM at the time of injection. These perturbations included a dramatic thickening of the neural epithelium in the posterior eye, a failure of cells in this region to elongate radially, formation of an ectopic optic fiber layer, and an incomplete association of the presumptive pigmented epithelium with the neural retina. These results provide the first direct evidence that the polysialic acid on NCAM has a regulatory effect on adhesion between living cells, and that the amount of this carbohydrate is critical for the normal morphogenesis of nerve tissue.
277 citations
TL;DR: Results demonstrate that RDE of influenza C virus is neuraminate‐O‐acetylesterase and indicate that haemagglutination‐inhibition (HI) by RMG and BSM and most likely virus attachment to cell surfaces involves binding of influenzaC virus to Neu5,9Ac2.
Abstract: The nature of the receptor-destroying enzyme (RDE) of influenza C virus has been elucidated by analyzing its effect on the haemagglutination inhibitors rat alpha 1-macroglobulin (RMG) and bovine submandibulary mucin (BSM), respectively. The inhibitory activity of both compounds is abolished by incubation with influenza C virus. After inactivation, RMG and BSM were found to contain reduced amounts of N-acetyl-9-O-acetylneuraminic acid (Neu5,9Ac2) and increased amounts of N-acetylneuraminic acid (Neu5Ac). H.p.l.c. analysis revealed that purified Neu5,9Ac2 is converted to Neu5Ac by incubation with influenza C virus. These results demonstrate that RDE of influenza C virus is neuraminate-O-acetylesterase [N-acyl-9(4)-O-acetylneuraminate O-acetylhydrolase (EC 3.1.1.53)]. The data also indicate that haemagglutination-inhibition (HI) by RMG and BSM and most likely virus attachment to cell surfaces involves binding of influenza C virus to Neu5,9Ac2.
238 citations
TL;DR: An acidic glycolipid antigen that reacts with monoclonal IgM in patients with demyelinating neuropathy and with the mouse monOClonal antibody, HNK-1, was purified from human peripheral nerves and suggested the following structure with a sulfate in a position that remains to be determined.
218 citations
TL;DR: The dual role of aldolase in dissimilating and detoxifying sialic acids is consistent with the apparent multiple controls on expression of this enzyme.
Abstract: Escherichia coli K-12 and K-12 hybrid strains constructed to express a polysialic acid capsule, the K1 antigen, were able to efficiently use sialic acid as a sole carbon source. This ability was dependent on induction of at least two activities: a sialic acid-specific transport activity, and an aldolase activity specific for cleaving sialic acids. Induction over basal levels required sialic acid as the apparent inducer, and induction of both activities was repressed by glucose. Induction also required the intracellular accumulation of sialic acid, which could be either added exogenously to the medium or accumulated intracellularly through biosynthesis. Exogenous sialic acid appeared to be transported by an active mechanism that did not involve covalent modification of the sugar. Mutations affecting either the transport or degradation of sialic acid prevented its use as a carbon source and have been designated nanT and nanA, respectively. These mutations were located by transduction near min 69 on the E. coli K-12 genetic map, between argG and glnF. In addition to being unable to use sialic acid as a carbon source, aldolase-negative mutants were growth-inhibited by this sugar. Therefore, the intracellularly accumulated sialic acid was toxic in aldolase-deficient E. coli strains. The dual role of aldolase in dissimilating and detoxifying sialic acids is consistent with the apparent multiple controls on expression of this enzyme. Images
218 citations
TL;DR: Restoration of agglutinability by WGA in neuraminidase-treated cells or cells grown in medium without fetal calf serum occurred equally well in energy-rich or energy-depleted cells.
189 citations
Journal Article•
TL;DR: Hanganutziu-Deicher (HD) antigen-active N-glycolylneuraminic acid (NeuGc)-containing gangliosides were isolated and characterized from human colon cancer tissues, and densitometric determination indicated that HD antigenic sialic acid, NeUGc, accounted for about 1% or less of the total lipid-bound sialIC acids.
Abstract: Hanganutziu-Deicher (HD) antigen-active N-glycolylneuraminic acid (NeuGc)-containing gangliosides were isolated and characterized from human colon cancer tissues. The antigenic gangliosides were detected by thin-layer chromatography by our newly developed method (H. Higashi, Y. Fukui, S. Ueda, S. Kato, Y. Hirabayashi, M. Matsumoto, and M. Naiki. J. Biochem., 95: 1517-1520, 1984) of enzyme immunostaining using affinity-purified chicken antibody against hematoside containing NeuGc (II3NeuGc-LacCer) and horseradish peroxidase-conjugated rabbit anti-chicken lgG. One to six species of the antigenic gangliosides were isolated from seven of 16 cases of colon cancer, whereas no antigenic compound was detected in all apparently normal colorectal tissues from 17 individuals without colorectal cancer. Tissues from different patients showed different patterns of molecular species of the antigenic gangliosides. Densitometric determination indicated that HD antigenic sialic acid, NeuGc, accounted for about 1% or less of the total lipid-bound sialic acids. Four species of antigenic gangliosides were identified as hematoside and hematoside-containing O-acyl ester (II3NeuGc-LacCer and II3 4- or 7-O-acyl-NeuGc-LacCer), GM2-containing NeuGc (II3NeuGc-GgOse3Cer), and sialylparagloboside (IV3NeuGc-nLcOse4Cer) by their behaviors on 2-dimensional thin-layer chromatography, and the effects of mild alkaline treatment, sialidase treatment, periodate oxidation, and endo-beta-galactosidase treatment.
188 citations
TL;DR: The results indicate that both GD2 and GM2 expressed on human melanoma cells are immunogenic in humans, although GM2 appears to be more immunogenic.
Abstract: The immunogenicity of gangliosides found on human melanoma cells was determined from sera of 26 melanoma patients who were immunized every 1–4 weeks for 4 months with tumor-cell vaccine (TCV) prepared from cultured melanoma cells. Total lipidbound sialic acid in the gangliosides isolated from TCV was 0.38 μmol/108 cells, and was distributed as follows: 44.8% to GM3, 44.2% to GD3, 5.6% to GM2, and 4.6% to GD2. Sera were tested at monthly intervals for antibodies to each ganglioside by ELISA with purified gangliosides as the antigen source. The immunologic specificity of the antibody was confirmed by absorption tests. None of the 26 patients had detectable anti-GM3, anti-GD3, or anti-GD2 antibodies before immunization, although anti-GM2 antibody was detected in 3 patients. After immunization, 2 patients developed IgM anti-GD2, 10 developed IgM anti-GM2, and 2 developed IgG anti-GM2 antibodies. No patient developed detectable anti-GM3 or anti-GD3 antibodies. These results indicate that both GD2 and GM2 expressed on human melanoma cells are immunogenic in humans, although GM2 appears to be more immunogenic. The other two gangliosides, GM3 and GD3, are present in human sera and in human normal tissues, and thus immunologic tolerance may have been established against these gangliosides. Alternatively, circulating GM3 and GD3 may have neutralized anti-GM3 and anti-GD3 antibodies, if any were induced by TCV immunization.
182 citations
TL;DR: The results indicate that the brain polysialosyl glycopeptides contain a longPolysialic acid segment, which is also specifically needed for certain molecular interactions, which was found to require 10 residues or more for binding.
167 citations
TL;DR: Analysis of glycolipids isolated from granulocytes, erythrocytes, and whole blood cells revealed that, among the gly colipids prepared from the whole blood Cells, dihexaosylceramide, lactoneotetraosyl Aceramide, and the above described linear lactoneo series neutral glycolIPids are present in granulocyte but barely present in ery Throcytes.
TL;DR: These proline-rich glycoproteins induced in mouse parotid and submandibular glands by isoproterenol treatment have high affinities for tannins as demonstrated by competitive binding curves and appear to be identical by amino acid compositions, glycopeptide analysis, and preliminary amino acid sequencing data.
TL;DR: The results indicate that gangliosides have complex effects on membrane‐associated kinase activities and suggest that Ca2+ ‐ganglioside complexes are potent stimulators of membrane kinase activity.
Abstract: The effects of gangliosides on phosphorylation were studied in rat brain membrane. Gangliosides stimulated phosphorylation only in the presence of Ca2+ with major phosphoproteins of 45,000, 50,000, 60,000, and 80,000 daltons and high-molecular-weight species. In addition, gangliosides inhibited the phosphorylation of three proteins with molecular weights of 15,000, 20,000, and 78,000 daltons. The two low-molecular-weight proteins comigrated with rat myelin basic proteins. Ganglioside stimulation was dependent on the formation of a Ca2+-ganglioside complex since the calcium salt of gangliosides stimulated phosphorylation maximally. Disialo and trisialo gangliosides were more potent stimulators of kinase activity than the monosialo GM1 X GD1a was the most potent activator tested. Asialo-GM1, cerebroside, sialic acid, neuraminyllactose, sulfatide, and the acidic phospholipids phosphatidylserine and phosphatidylinositol did not stimulate kinase activity. The Ca2+-dependent, ganglioside-stimulated phosphorylation was qualitatively similar to the pattern for calmodulin-dependent phosphorylation. However, while calmodulin-dependent kinase activity was inhibited with an IC50 of 10 microM trifluoperazine, ganglioside-stimulated kinase was inhibited with an IC50 of 200 microM trifluoperazine. These results indicate that gangliosides have complex effects on membrane-associated kinase activities and suggest that Ca2+-ganglioside complexes are potent stimulators of membrane kinase activity.
TL;DR: The results indicate that the hemagglutinin of influenza virus A/Aichi/2/68 (H3N2) recognizes the sialyloligosaccharide chain of ganglioside GM3 as its receptor which mediates the adsorption and fusion process on the virus entry into the host cells and has more preferential specificity for binding to N-acetylneuraminic acid-containing GM3 in the target cell membranes.
TL;DR: The results suggest that recognition of the various sialic acids is an important factor in analysis of the receptor specificity of influenza virus hemagglutinins.
TL;DR: The results indicate that at low ionic strength and physiological Ca2+-concentration and pH, the surface charge of LDL is an important modulator of the interaction with the arterial proteoglycan.
TL;DR: It is shown that sialic acid aldolase can regulate the intracellular concentration of sIALic acid and therefore the concentration of CMP-NeuNAc, and direct evidence for the central role of a Aldolase in regulating the metabolic flux of siali adid in E. coli is provided.
Abstract: In Escherichia coli, synthesis of sialic acid is not regulated by allosteric inhibition mediated by cytidine 5'-monophospho-N-acetylneuraminic acid (CMP-NeuNAc). Evidence for the lack of metabolic control by feedback inhibition was demonstrated by measuring the intracellular level of sialic acid and CMP-NeuNAc in mutants defective in sialic acid polymerization and in CMP-NeuNAc synthesis. Polymerization-defective mutants could not synthesize the polysialic acid capsule and accumulated ca. 25-fold more CMP-NeuNAc than the wild type. Mutants unable to activate sialic acid because of a defect in CMP-NeuNAc synthetase accumulated ca. sevenfold more sialic acid than the wild type. An additional threefold increase in sialic acid levels occurred when a mutation resulting in loss of N-acylneuraminate pyruvate-lysase (sialic acid aldolase) was introduced into the CMP-NeuNAc synthetase-deficient mutant. The aldolase mutation could not be introduced into the polymerization-defective mutant, suggesting that any further increase in the intracellular CMP-NeuNAc concentration was toxic. These results show that sialic acid aldolase can regulate the intracellular concentration of sialic acid and therefore the concentration of CMP-NeuNAc. We conclude that regulation of aldolase, mediated by sialic acid induction, is necessary not only for dissimilating sialic acid (E.R. Vimr and F. A. Troy, J. Bacteriol. 164:845-853, 1985) but also for modulating the level of metabolic intermediates in the sialic acid pathway. In agreement with this conclusion, an increase in the intracellular sialic acid concentration was correlated with an increase in aldolase activity. Direct evidence for the central role of aldolase in regulating the metabolic flux of sialic adid in E. coli was provided by the finding that exogenous radiolabeled sialic acid was specifically incorporated into sialyl polymer in aldolase-negative strain but not in the wild type.
Journal Article•
TL;DR: The data indicate that the reduced total glomerular sialic acid content found in PAN is due to the combined effects of the decreased podocyte plasmalemmal surface area and the reduced sialIC acid content of podocalyxin.
Abstract: In this study the sugar composition of podocalyxin was determined in puromycin aminonucleoside-treated (PAN) rats and controls Podocalyxin from both control and PAN rats bound 125I-WGA and 125I-peanut lectin (the latter only after neuraminidase treatment) on nitrocellulose transfers Purified podocalyxin from both control and PAN rats was found to contain sialic acid, Gal, GlcNac, and Man but lacked Fuc and GalNac by gas-liquid chromatography In PAN rats the sialic acid content of podocalyxin was reduced from 45% to 15%, whereas the concentration of the other sugars (with the possible exception of Gal) was similar to that of controls The density of podocalyxin on the epithelial cell surface was estimated after immunogold labeling with anti-podocalyxin IgG, and no differences were found between PAN rats and controls These data indicate that the reduced total glomerular sialic acid content found in PAN is due to the combined effects of the decreased podocyte plasmalemmal surface area and the reduced sialic acid content of podocalyxin
TL;DR: A glycolipid antigen, detected by a monoclonal antibody obtained by immunizing mice with a human metastatic melanoma cell line, was isolated and structurally characterized and revealed only this ganglioside in the melanoma cells, while normal human brain was negative.
TL;DR: The biosynthesis of the sialyl-Lea antigen proceeds by addition of sialic acid to a type 1 precursor chain by a sIALyltransferase, followed by addition to fucose by the Lewis fucosyl transferase, as well as using glycolipid precursors.
TL;DR: The combined use of these procedures distinguished the four different types of N-linked glycoproteins from sheep red blood cells.
TL;DR: Using a combination of the two procedures, 32 different molecular species of GM1 ganglioside, over 99% homogeneous, have been prepared.
TL;DR: During the first 2 months of lactation, milk from women delivering at term cannot be distinguished from that of women delivering significantly before term (less than 32 wks gestation) with regard to oligosaccharide and glycoprotein NANA, and the parallel decrease of sialic acid in these fractions suggests a relationship between sialydation of human milk oligOSaccharides and Glycoproteins.
Journal Article•
TL;DR: The nature of the colominic acid-specific group B determinant was elucidated by a radioimmunoassay inhibition technique with the use of a series of linear alpha-(2----8)-linked oligomers of sialic acid as inhibitors.
Abstract: A meningococcal group B-specific horse antiserum contains at least two distinct populations of antibodies with specificities for determinants on the group B capsular polysaccharide antigen. These two populations were differentiated on the basis of the ability of only one of them to be absorbed from the antiserum by the structurally related colominic acid. The nature of the colominic acid-specific determinant was elucidated by a radioimmunoassay inhibition technique with the use of a series of linear alpha-(2----8)-linked oligomers of sialic acid as inhibitors. Colominic acid was labeled by prior removal of its N-acetyl groups, followed by their replacement with the use of [3H]acetic anhydride. The conformational nature of the determinant was proposed because of the unusually large size (10 sialic acid residues) of the oligomer required to function as an efficient inhibitor. The structure of the determinant responsible for the second population of group B-specific antibodies has not been determined, but it is obviously based on an as yet undefined conformational or structural feature peculiar to the group B meningococcal polysaccharide. In contrast to the colominic acid-specific group B determinant, the determinant responsible for the group C polysaccharide-specific rabbit antibodies proved to be more conventional. Inhibitory properties of the alpha-(2----9)-linked oligomers maximized with those containing four or five sialic acid residues, which is consistent with the approximate estimated maximal size of an antibody site.
TL;DR: Glycoproteins and oligosaccharides were extracted from meconium samples of group O neonates of secretor type by pronase digestion followed by precipitation in 67% aqueous ethanol and separated into Ii antigen enriched and depleted fractions by affinity chromatography.
Abstract: Glycoproteins were extracted from meconium samples of group O neonates of secretor type by pronase digestion followed by precipitation in 67% aqueous ethanol and separated into Ii antigen enriched and depleted fractions by affinity chromatography. The latter fraction strongly expressed the oncofoetal antigens recognised by natural antibodies in mouse sera and the hybridoma antibody FC 10.2, and this activity was enhanced after mild acid hydrolysis to remove sialic acid and fucose residues. Oligosaccharides were released from the mild-acid-treated fraction by base-borohydride degradation and purified by gel permeation chromatography on Bio-Gel P4 and high performance liquid chromatography on octadecylsilyl and aminopropylsilyl columns. The major oligosaccharides were characterised by fast atom bombardment and electron impact mass spectrometry, combined gas-liquid chromatography/mass spectrometry and 500-MHz proton NMR spectroscopy. Their structures, in order of abundance, were:
TL;DR: The reversion of the avian virus variants in eggs provides compelling evidence for host-mediated selection of influenza virus receptor variants.
TL;DR: NANA and LSA show promise as supplemental markers for staging and monitoring colorectal cancer, but they are neither sensitive nor specific enough for cancer screening.
Abstract: Concentrations of total serum N-acetyl-neuraminic acid (NANA) by high-performance liquid chromatography (HPLC) and lipid-bound sialic acid (LSA) by resorcinol procedure were evaluated and compared to carcinoembryonic antigen (CEA) as markers for colorectal carcinoma. Elevated concentrations of NANA were found in 32% of patients with nonmalignant disorders, 28% of patients with localized cancer, and 87% of patients with metastatic cancer. All three markers correlated with the extent of metastasis of colorectal carcinoma. Strong correlation was found between NANA and LSA measurements, whereas measurement of the sialic acid markers provide information that can not be derived from the measurement of CEA. NANA and LSA show promise as supplemental markers for staging and monitoring colorectal cancer, but they are neither sensitive nor specific enough for cancer screening.
TL;DR: The studies on the structures of the oligosaccharide moieties of the mature EGF receptor and its precursor suggest that in A-431 cells blood group determinants in surface glycoproteins are contained in Asn-linked but not O-linked oligOSaccharides.
TL;DR: The fetal antigen in fetal brain is specifically associated with regions of neuronal sprouting and, therefore, can be used as a molecular marker of neurite growth.
Abstract: This study describes the preparation of a membrane subfraction from isolated nerve growth cone particles (GCPs) (see Pfenninger, K. H., L. Ellis, M. P. Johnson, L. B. Friedman, and S. Somlo, 1983, Cell, 35:573-584) and the identification in this fraction of a glycoprotein expressed during neurite growth. While approximately 40 major polypeptides are visible in Coomassie Blue-stained SDS polyacrylamide gels of pelleted (partially disrupted) GCPs, a salt-washed membrane fraction prepared from lysed, detergent-permeabilized GCPs contains only 14% of this protein and has an unusually simple polypeptide pattern of seven major bands. Monoclonal antibodies have been generated to GCP membranes isolated from fetal rat brain. These antibodies have been screened differentially with synaptosomes from adult rat brain in order to identify those which recognize antigens expressed selectively during neurite growth. One such antibody (termed 5B4) recognizes a developmentally regulated membrane glycoprotein that is enriched in GCP membranes and expressed in fetal neurons sprouting in vitro. The 5B4 antigen in fetal brain migrates in SDS polyacrylamide gels as a diffuse band of approximately 185-255 kD, is rich in sialic acid, and consists of a small family of isoelectric variants. Freezing-thawing and neuraminidase digestion result in the cleavage of the native antigen into two new species migrating diffusely around 200 and 160 kD. Prolonged neuraminidase digestion sharpens these bands at about 180 and 135 kD, respectively. In the mature brain, antibody 5B4 recognizes a sparse polypeptide migrating at approximately 140 kD. As shown in the following paper (Wallis, I., L. Ellis, K. Suh, and K. H. Pfenninger, 1985, J. Cell Biol., 101:1990-1998), the fetal antigen is specifically associated with regions of neuronal sprouting and, therefore, can be used as a molecular marker of neurite growth.
TL;DR: By simple re-N-acylation of lysogangliosides with any labeled fatty acid, labeled ganglioides are now obtainable that are identical with their parent ganglioside except for their labeled fatty acids residue.
Abstract: The synthesis of gangliosides GM3, GM2, GM1, and GD1a solely lacking the fatty acid moiety, and thus called lysogangliosides in analogy to lysophospholipids, is described. Since a selective elimination of the fatty acid residue has not been achieved as yet, the gangliosides were first subjected to alkaline hydrolysis. By this procedure the fatty acyl as well as the acetyl groups of the sialic acid residue(s) were completely removed. The acetamido group of the N-acetylgalactosamine moiety of the gangliosides GM2, GM1, and GD1a was very little (congruent to 10%) hydrolyzed. In a two-phase system composed of water and ether, the selective protection of the sphingoid amino group was accomplished with a hydrophobic protective group (9-fluorenylmethoxycarbonyl). Lysogangliosides were obtained after re-N-acetylation of the sialooligosaccharide amino group(s) followed by removal of the protecting group. The overall yield was about 30%. The structures of the lysogangliosides were confirmed by chemical analysis as well as negative ion FAB mass spectrometry and 1H NMR spectroscopy. By simple re-N-acylation of lysogangliosides with any labeled fatty acid, labeled gangliosides are now obtainable that are identical with their parent gangliosides except for their labeled fatty acid residue. This has been demonstrated by the synthesis of GM1 with a [1-13C]palmitic acid moiety in its ceramide portion. If desired, double-labeled gangliosides may be obtained by use of labeled acetic anhydride in the synthesis of the lysogangliosides.